Henri victoe jules jotjeeret



Patented Dec. 16,1919.

SPARKING PLUG.

* APPLICATION FlLI ID IUNE 10, 1918.

H. V. J. LOUFFRET.

STATES PATENT OFFICE.-

HENRI VICTOR JULES JOUFFRET, or NEUILLY-ISUR-SEINE, FRANCE.

SPARKING PLUG.

' specification.

This invention relates to sparking plugs for internal combustion engines.

It has for its principal object the construction of articles of the class in question in such a manner that the gases entering the space at the lowerpart of the "casingof the plug do not raise it to-too high a temperature, the construction being moreover more simple, effective and economical than that of such devices as already in use.

The invention refers to that type of sparking plug, having one extremity of the casing, namely the one connected to the combustion chamber of the motor, to which the device is 'fitted, provided with a plurality of passages, adapted to put the interior of the said easing into communication with the .combustion chamber of the motor, one of the passages, namely that where the ignition takes place, being relatively large in section, and the others relatively small and it consists, in so constructing the device that the passages do not open directly into the interior "ofthe casing but into a secondary chamber separated by a constricted portion on the interior from the said interior of the casing and in providing the said passages in an independent part extending into and fixed in the said casing.

In addition to the foregoing principal constructional features, which are preferably employed incombination, the invention comprises. other features which will be more fully described hereafter.

.It includes certain constructional embodiments of the 'said' improvements, de-

vices comprising the said improvement, as new articles of manufacture, and special parts suitable for their construction.

In order that the said invention may be clearly understood, I will now proceed to describe the same with reference to the .accompanying drawing, which however. is

given merely by way of example.

Figure 1 of the'said drawing is an mal Specificationof Letters Patent. I

Application filed June 10,v 1918. Serial No. 239,252.

sectional view of a sparking plug constructed according to the invention. I

Fig.2 is a-plan of the electrodeblock connected to the bodyportion of the said plug."

In the method of carrying out the invention represented in the drawing, I.'-make the sparking plug with a casing a, in the interior of which is an insulated electrode 6 surrounded by an insulator c, andI mount theelectrode (Z in the extremity of the easing a which screws into the motor so-that it comes at a short distance from the extremity of the insulated electrode bf.

.It is desirable" to prevent the gases as, they pass intothe interior a of the casingthat is to say, between the insulator cfand the inner wall of'the casing-45mm having too high a temperature with the consequent effect of causing rapid deterioration of the insulator c. F or this purpose I provide in that extremity of the casing 0;, which-opens into the combustion chamber of the motor, a plurality of passages connecting the interior a .of the casingfwith the 'saidfcombustion chamber, one of, these passages d namely the one in which the ignition takes place being of relatively large section while the others (Z are of relatively small section.

just explained, according togmy invention, in place of'causing the passages d and d? to open directly into the interior a of the:

lindrical extremity of the casing, thechan 1 her a being separated from the chamber a by a constriction a on the interior.

iece' or block. .-projecting into be inserted inthe cylindrical extremity of the casing: and with this-end" in view, I make the electrode d from'a;cylin,--

- In addition to adopting the construction I chamber, I so arrange that they open intoa secondary chambera provided in-the cy I 1 Moreover, I prefertoprovidetthe passages d and d in a or adapted to drical block, the outer diameter of which is equal to the inner diameter of the casing a. In the said cylindrical block, I drill a cenof the extremity tral hole al into the interiorof which the point of the insulated electrode 03 extends when the parts are assembled, and I rovide around the periphery of the said cylmdrical block a plurality of grooves or recesses (1 I fix the said cylindrical block 03 in the so s5 extremity of the casing at, either by forcing it into position, as shown, or I may prov de it with a screw thread adapted to screw into a corresponding screw thread in the casing a.

temperature of the gases in t e interior a of the chamber, the cooling efiect being in-;

creased owing to the fact that the gases passing through the different passages are agitated and the flow broken up in passing through the constricted portion a before penetrating into the interior a of the chamber.

It is to be understood that the invention is not limited to the particular method of carrying the same into effect which has been more particularly described, butthat it includes such modified constructions as come within a fair interpretation of my claims.

Claims.- 1. A sparking plug comprising a casing for connection with the combustion chamber of the motor and a cylindrical electrode block fitted into the lower end of saidcasing and conforming in external diameter to the internal diameter of the portion of the cas; ing in which it is fitted, said block having a plurality of passages to establish communication between the combustion chamber and the interior chamber of said casing, said casing having a secondarychamber between said passages and said interior chamber and having an interior constriction between said secondary and interior chambers.

2. A sparking plug comprising a casing for connection with the combustion chamber of the motor and a cylindrical electrode block fitted into the lower end of said casing and conforming in external diameter to the interior diameter of the portion of the casing in which it is fitted, said block having a plurality of passages to establish communication between the combustion chamber and the interior of said casing and having said passages constituted by grooves formed in its periphery and by a central opening of relatively large section as compared with said grooves, said casing having a secondary chamber betweensaid passages and said interior chamber and having an interior constriction between said secondary and interior chambers.

In testimony whereof I have hereunto set I my hand in presence of two subscribing witnesses.

HENRI VICTOR JULES JOUFFRE'I. Witnesses:

EUGENE VILLIER, Crms. P. PRESSLY. 

